From: N2EY
Date: Sun, 2 May 2010 12:32:32 EDT
On May 1, 1:43 pm, John from Detroit wrote:

K0HB wrote:
Better in what way?
Better in that it's more advanced..

For example, the R-390 and R-390A were designed way back in the early
1950s, and one of the requirements was a digital frequency readout.

Not quite. The "digital frequency readout" was done for several
reasons. Collins Radio was heavy into a LINEAR FREQUENCY tuning
scheme using permeability tuning rather than variable capacitors.
This is witnessed in the predecessors which used a combination of
LF to HF receivers having straight-line scales in addition to
the rotary dial around the main tuning knob.

Linear frequency tuning was also adopted by the consumer radio
manufacturers, particularly for auto radios having automatic seek
systems that appeared in the very late 1940s and early 1950s. It
was advantageous to the cheap servo systems used there. Such
"signal seeking" tuning would disappear for quite a while until
solid-state tuning systems (much cheaper) would appear in 30 years.

The (LF) R-389 and (HF) R-390 series were required to tune a
wider band of frequencies with relatively the SAME sensitivities
across the whole span of tuning. That was unlike the older
systems which had a large disparity of sensitivity due to ganged
variable capacitor tuning in previous multi-band HF designs. The
TUNING RATE was linear on all bands of the 390 series, advantageous
to the R-391 "Autotune" version of the basic 390 series (Collins
was big on "Autotuning" everything they could back in the 1950s
and 1960s). Using the common mechanical turns-counter of machinery
('Veeder-Root'as an example of type) offered a great physical
advantage in the 390 series since it did away with the space
needed for a straight-line indicator. The gear-cam-geneva-wheel
mechanical coupling could be fitted in easier than that long
(sometimes rotating on axis) scale. All of the permeability-tuning
L-C circuits could be adapted to track straight-line tuning easier
than using (bulkier) variable capacitors. There was physical
space to incorporate the "Autotune" servo system (R-391) without
undue change of the R-390 physical structure. That the 390 series
was "digital" is like saying a whole lot of metal-working equipment
was "digital" in the 1930s because they used Veeder-Root counters
having decimal digit indication.

Main Source: Collins Radio "Final Engineering Report" 15 Sep 53,
submitted to U.S.Army Signal Corps, contract W36-039-SC-44552,
scanned by Al Turevold, WA0HQQ on 18 Apr 99.

I suspect that the use
of ham gear in military applications came about only when nothing else
was available at the time.

In the historical sense, the word "ham gear" should be replaced by
"commercial users" especially in the period 1910 to 1970. Before
the commsats, before the transcontinental microwave relay network,
before the self-pumped fiber-optic-laser lines, the ONLY long-
distance comm paths for commercial use was HF. SSB on HF was
pioneered commercially from the early 1930s onward (Netherlands
being the first to introduce voice and TTY service 24/7 to
Netherlands Antilles). MARS was never an integral part of the
worldwide military tactical communications of the USA.
The AN/FRC-93 is a KWM-2 by virtue of its label, nothing else,
was used by MARS stations for morale purposes...much like a Zenith
"Trans-Oceanic" portable receiver procured for troops during WWII.
A difference was that this Trans-Oceanic was actually painted
olive drab. :-)

Remember too that a lot of ham gear and components (such as the PTOs
developed by Collins) were originally developed for military
applications and then used for ham stuff.

That seems anecdotal and subjective. Resistors, capacitors,
inductors, fastening devices, blank chassis and cabinets, et al
were all developed by INDUSTRY standards, not just military. Rack
cabinets came from the telephone infrastructure. Teleprinter code
format came from the computer industry. Collins "mechanical" (
magnetostrictive) filters were done first for the microwave radio
relay frequency multiplexer market. Modern USA amateur radio
design owes almost everything new to innovative Japanese
communications equipment designers. The US Army went to VHF
voice for short-range communications IN WWII and kept doing that
until now. Long-haul communications of the US military and
government is over the DSN (Digital Switched Network) which can
use any comm path or relay method plus is compatible with the
standard telephone infrastructure. USA submarines use ELF for
Alerts and nuke subs don't have any OOK CW capabilities.

Cellular telephony developed all by itself, by the telephone
industry, owing nothing technological to the military. Roughly
100 million cell phones are now in the USA alone. Digital
television owes nothing to any military yet the USA switched over
entirely in TV broadcasting to DTV (the first and second NTSC
systems did not come from military requirements). CB on 11m
(roughly 5 million users) owes nothing to the military. FM
stereo broadcasting owes nothing to the military. Medical
electronics communications owes very, very little to the
military in technology. All of those are RADIO applications.

73, Len K6LHA